The present invention relates to an apparatus for clamping a sheet round a drum usually provided in facsimile apparatus, copying apparatus, or printing apparatus, and more specifically to a clamp apparatus comprising a single clamp member positioned along a generating line of the drum and at part of the peripheral surface of the drum which clamps an original sheet for transmission, or a recording paper for reception in the case of facsimile apparatus, or a photoconductive sheet in the case of copying apparatus, or a master plate in the case of printing apparatus.
In the conventional clamp device of this sort, the front edge and the rear edge of a sheet to be wound round the drum are separately clamped by different clamp members positioned at the peripheral surface of the drum, that is, one clamp member for the front edge and the other for the rear edge of a sheet.
Thus, in order to clamp the front edge of a sheet on the drum, it is necessary to open and close one clamp member for the front edge and the other clamp member for the rear edge, respectively, with a proper timing. However, this results in inconvenience, for the clamp members become complicated in the operation mechanism.